Adjustment apparatus for stirrup assembly including rotating clamp bracket

ABSTRACT

A mechanism is disclosed for permitting vertical and angular adjustment of a stirrup assembly located at either side of the foot end of a medical examination table. The assembly includes a clamping bracket pivotally secured to a horizontally extending extension bar. When the bracket is in a lowered position, it clamps the stirrup support rod and fixes the position of the stirrup assembly. When the bracket is raised, either by raising the bracket itself or by pulling the stirrup assembly, the stirrup support rod is released and the stirrup assembly may be adjusted.

United States Patent [191 Mueller et a1.

ADJUSTMENT APPARATUS FOR STIRRUP ASSEMBLY INCLUDING ROTATING CLAMP BRACKET Inventors: Floyd F. Mueller, Two Rivers;

Clarence J. Aulik, Manitowoc, both of Wis.

American Hospital Supply Corporation, Evanston, 111.

Filed: Feb. 5, 1973 Appl. No.: 329,378

Assignee:

US. Cl. 269/328, 24/249 FP, 403/235 Int. Cl A6lg 13/00 Field of Search 24/249 R, 249 SA, 249 PP; 248/231; 269/328; 287/54 C; 403/235;

References Cited UNITED STATES PATENTS 3/1898 Hill 24/249 SA July 16, 1974 1,297,351 3/1919 Horton 24/249 SA 1,384,619 7/1921 McRae 24/249 SA 3,612,509 10/1971 Boston 269/328 Primary ExaminerRoy Lake Assistant ExaminerNeil Abrams Attorney, Agent, or FirmDawson, Tilton, Fallon & Lungmus 5 7] ABSTRACT A mechanism is disclosed for permitting vertical and angular adjustment of a stirrup assembly located at either side of the foot end of a medical examination table. The assembly includes a clampingbracket pivotally secured to a horizontally extending extension bar. When the bracket is in a lowered position, it clamps the stirrup support rod and fixes the position of the stirrup assembly. When-the bracket is raised, either by raising the bracket itself or by pulling the stirrup assembly, the stirrup support rod is released and the stirrup assembly may be adjusted.

7 Claims, 7 Drawing Figures BACKGROUND AND SUMMARY The present invention relates to a mechanism for adjusting the stirrup assembly such as are found at either side of the foot end of a medical examination table. Typically, each stirrup assembly is secured to a horizontally extensible support bar which is received in the table and adjustable by loosening and tightening a hand wheel.

The stirrup assembly is located at the end of the extensible support bar, and the stirrup itself is supported on a rod which is clamped to the extensible stirrup support bar by means of a second hand wheel assembly. Thus, prior mechanisms for adjusting stirrup assemblies vertically and angularly have heretofore required the use of two hands, one for turning the hand wheel and the other for holding and adjusting the stirrup assembly. This is inconvenient for the treating physician. Further, it normally requires considerable force to securely clamp a stirrup assembly with a hand wheel, and it will be realized that for treatment or examination, the stirrup assemblies must be firmly and rigidly clamped so as not to come loose and possibly cause the patient to lose balance.

The present invention includes apparatus for clamping a stirrup support rod while permitting adjustment. Both the clamping and adjusting operations require 1 only a single hand to accomplish.

In the present invention, a U-shaped bracket is mounted to a horizontal extension bar for pivotalmotion about a horizontal axis between a raised and a lowered position. In the lowered position, the bracket extends beyond the distal edge of the extension bar and cooperates with it to provide a receptacle for the stirrup support rod, clamping it in place.

In one embodiment, a resilient, compressible brake pad is secured to either the extension bar or the bracket to engage the rod and clamp it rigidly when the bracket is lowered after the rod has been adjusted. In another embodiment, a dowel pin is fitted into the endof the extension bar and adapted to engage and secure the rod when it is lowered.

When the bracket is raised, either by grasping the bracket itself or by pulling the clamped rod upwardly, it brakes into an unlocked position, releasing the clamping pressure on the rod and thereby permitting adjustment of the stirrup assembly. Thus, with the present invention, a stirrup assembly can be adjusted in elevation or angular disposition quite easily and with the motion of a single hand. Further, the present invention offers greater reliability in clamping the stirrup assembly in the locked position than has heretofore been realized with the prior hand wheel assemblies because in the present invention, when weight is applied to the stirrup assembly, it tends to force the bracket as well as the stirrup rod downwardly and because of the shape of the receptable, this induces an even tighter clamping force on the rod.

Other features and advantages of the present invention, including better appearance and lower manufacturing costs, will be apparent to persons skilled in the art from the following detailed description of a preferred embodiment accompanied by the attached drawing wherein identical reference numerals will refer to like parts in the various views.

THE DRAWING FIG. 1 is a fragmentary upper perspective view taken from the foot end of a medical examination table incorporating the present invention;

FIGS. 2 and 3 are fragmentary top and side views respectively of an improved mechanism for vertically adjusting a stirrup assembly;

FIGS. 4 and 5 are fragmentary top and side views of a modified stirrup adjustment mechanism respectively;

'still another embodiment of the invention."

DETAILED DESCRIPTION Referring first to FIG. 1, reference numeral 10 generally designates a medical examination table including first and second adjustable stirrup assemblies 11. Each of the stirrup assemblies 11 is similar in structure and operation but designed to accommodate either a left or a right foot. Hence, only one of the stirrup assemblies need be described in detail for a full appreciation of the invention.

Each stirrup assembly includes a stirrup 12 secured by a support rod including an upper inclined portion 13 and a lower vertical portion 14. Each of the stirrup a'ssemblies 11 is adjustable in a horizontal direction away from the foot of the table 10 by means of an extensible horizontal bar 15 secured by a conventional hand wheel 16. The mechanism for horizontal adjustment forms no part of the present invention, and will not be further discussed.

Turning now to FIGS. 2 and 3, it will be observed that the extension bar 15 is rectangular in cross section, having a greater depth than width. The distal edge of the extension bar 15 is designated by reference numeral l7, and as best seen in FIG. 3, the upper corner 18 is rounded to form a smooth transition between the top 19'and the distal edge 17. Turning now to FIG. 2,

bar 15 by means of a pin 25 for rotation about a horizontal axis. First and second spacer members 26 and 27 are welded to the inner sides of the arms 22, 23 respectively to fill the space that would otherwise exist between these arms and the sides of the extension bar 15. It will be observedthat the curved portion 21 of the bracket 20 is designed to wrap aboutthe periphery of the vertical portion 14 of the stirrup support rod which has a diameter greater than the thickness of the extension bar 15.

. A pad designated 30 and formed of resilient, compressible material is secured to the inner surface of the curved portion 21 of the bracket 20 so as to engage the outer periphery of the vertical portion 14 of the stirrup curved portion 21 ofthe locking bracket 20 cooperates with the distal edge 17 of the extension bar 15 to prorod 14 and clampingit against rotational movement and against further downward movement. Rather, a downward force on the stirrup'support rod will urge the bracket further downwardly, and because of the frictional force between the rod 14 and the pad 31), the lower edge 32 of the curved portion 21 of the locking bracket 20 will be urged inwardly against the rod, therebyincreasing the clamping pressure. This action is enhanced because the lower outer corner 33 of the extension rod 15 is squared, asillustrated in FIG. 3.

In order to release the clamp so as to adjust the height or angular disposition of the rod 14, the U- shaped clamping bracket 22 is pulled upwardly, as seen in FIG. 6, thereby disengaging the rod from the outer bearing surface 17 of the extension bar 15. It will be observed that the clamping bracket 20 may be thus raised and lowered between the release and the locking positions either by grasping the bracket itself or by urging any portion of the stirrup assembly 11 due to the frictional contact between the pad 30 and the-outer periphery of the stirrup support rod.

A modification of the mechanism just described is illustrated in FIGS. 4 and 5; however, the operation just described is identical for the modified structure. Turning then to FIGS. 4 and 5, reference numeral again designates the horizontal extension bar, 17 designates the outer distal edge of the bar 15 which, in this embodiment does not form a bearing surface but, rather, is displaced slightly inwardly from the rod 14 even in .the locked position shown in FIG. 5. Again,'the upper outer edge of the extension bar is curved as at 18.

The clamping bracket 20, the spacers 26, 27 and the attachment of the bracket to the bar 15 are also similar to that which has already been described. In this embodiment, however, the lower outer edge of the ex.- tension bar 15 is notched at 40 in the form of a transverse channel, and a pad 41 of resilient, compressible material is attached to the bar 15 to fill the notch 40. The pad 41 extends slightly beyond the distal edge 17 of the extension bar 15. In this embodiment, the inner surface of the curved portion 21 of the clamping bracket 20 directly engages the rod 14.

Turning now to the modification illustrated in FIG. 7, reference numeral 15 again designates the horizontal extension bar, 17 designates the outer distal edge of the bar 15, and 18 designates the upper curved portion of the extension bar 15. This embodiment also includes a U-shaped clamping bracket 20, provided with a curved portion 21, and spacers similar to the above-described embodiments.

In this embodiment, a dowel pin 45 is fitted into an aperture 46 formed in the extension bar 15. The center of the dowel pin 45 is adjacent the distal edge 17 of the extension bar 15, and theaxis of the dowel pin 45 is parallel to the axis of rotation of the clamp bracket 20-that is, it is transverse to the axis of the support rod 14 for the stirrup assembly.

The dowel pin 45 is further located so as to project slightly outwardly of the flat edge 17 of the extension bar 15 to engage the rod 14 when the bracket- 20 is in its clamping position. In other words, the rod 14 is clamped between the curved portion 21 of the bracket 20 and the exposed surface of the dowel pin 45. The stirrup rod may be adjustedto its desired height with one hand. As the stirrup rod is moved to a vertical,

clamped position, the rod 14 pivots on. the exposed surface of the dowel pin 45, causing the rod to be clamped between the bracket 20 and the pin 45. Although it is notshown, a resilient pad may be used in conjunction with the pin 45, similar to that which is shown in the embodiment of FIGS. 2 and 3, although it is not necessary. Further, the illustration shows a solid dowel pin 45, but a spring steel roll pin may equally well be used, and in this latter case, the rod would slightly compress the roll pin, aiding the locking action.

It will be observed that the location of the pivot pin 25 of the embodiments of FIGS. 4 and 5 is raised rela-- tive to the previous embodiment, compare FIGS. 3 and 5. In the embodiment of FIG. 3, the location of the pivot pin 25 may vary with the thickness and location of the pad 30. However, it will be appreciated that in both embodiments when the U-shaped bracket clamps the stirrup support rod in the lowered position, any further downward force tends to enhance the clamping pressure; yet the clamping pressure is easily andtotally released when the rod or bracket is urged upwardly and pivoted, as already described.

The present invention thus provides an economical mechanism for clamping a stirrup support rod while those disclosed while continuing to practice the principle of the invention; and it is, therefore, intended that all such modifications be covered as they are embraced within the spirit and scope of the appended claims.

We claim:

1. In a medical examination table, a mechanism for clamping a stirrup assembly having a support rod while permitting vertical and angular adjustment of the stirrup assembly comprising: a horizontal extension bar extending from the foot end of said table and having a distal edge; an integral U-shaped bracket having a curved portion and first and second arms extending therefrom,

said arms being pivotally mounted to said bar for rotation about a horizontal axis whereby said bracket may be selectively moved between a raised release position and a lowered locking position in which said arms of said bracket are parallel to said extension bar, the curved portion of said bracket cooperating with said distal end of said extension-bar when said bracket is in said lowered position to provide a receptacle for said support rod; and means secured to one of said bar and said curved portion of said bracket for engaging and applying clamping pressure to said support rod when the same is receivedin the curved portion of said bracket and said bracket is located in said lowered clamping position.

2. The structure of claim 1 wherein said last named means is a pad fixed to the inner curved surface of. said bracket and extends substantially throughout the contact area-between said bracket and said rod, and wherein said rod engages said distal end of said extension bar in said clamping position, said extension bar being curved in the upper corner thereof adjacent said distal edge for facilitating rotation of said bracket to said release position.

3. The structure of claim 2 wherein the lower comer of said extension bar adjacent said distal edge is squared, whereby a downward force on said stirrup assembly will tend to further rotate said bracket and bring it into tighter clamping relation with said rod.

4. The structure of claim 1 wherein the lower corner of said bar adjacent said distal edge is notched and wherein said last named means is a compressible, resilient pad secured to said bar in said notch and extends slightly beyond said edge, said distal edge of said bar being spaced slightly from said rod in said locking positron.

5. The structure of claim 4 wherein the upper corner of said extension bar adjacent said distal edge is curved to facilitate rotation of said clamping bracket to said release position.

6. The structure of claim 4 wherein the height of said clamping bracket is substantially the same as the height of said bar and wherein the pivot position of said clamping bracket is above the vertical midpoint of said bar, whereby downward force is exerted on said stirrup assembly in a clamping position will enhance clamping action of said rod.

7. The structure of claim 1 wherein said bar is provided with a bore extending transverse of the axis of said support rod, said structure further comprising a dowel pin fitted in said bore and having an exposed lateral area extending beyond the distal end of said bar and adapted to engage said rod and clamp the same in said locking position. 

1. In a medical examination table, a mechanism for clamping a stirrup assembly having a support rod while permitting vertical and angular adjustment of the stirrup assembly comprising: a horizontal extension bar extending from the foot end of said table and having a distal edge; an integral U-shaped bracket having a curved portion and first and second arms extending therefrom, said arms being pivotally mounted to said bar for rotation about a horizontal axis whereby said bracket may be selectively moved between a raised release position and a lowered locking position in which said arms of said bracket are parallel to said extension bar, the curved portion of said bracket cooperating with said distal end of said extension bar when said bracket is in said lowered position to provide a receptacle for said support rod; and means secured to one of said bar and said curved portion of said bracket for engaging and applying clamping pressure to said support rod when the same is received in the curved portion of said bracket and said bracket is located in said lowered clamping position.
 2. The structure of claim 1 wherein said last named means is a pad fixed to the inner curved surface of said bracket and extends substantially throughout the contact area between said bracket and said rod, and wherein said rod engages said distal end of said extension bar in said clamping position, said extension bar being curved in the upper corner thereof adjacent said distal edge for facilitating rotation of said bracket to said release position.
 3. The structure of claim 2 wherein the lower corner of said extension bar adjacent said distal edge is squared, whereby a downward force on said stirrup assembly will tend to further rotate said bracket and bring it into tighter clamping relation with said rod.
 4. The structure of claim 1 wherein the lower corner of said bar adjacent said distal edge is notched and wherein said last named means is a compressible, resilient pad secured to said bar in said notch and extends slightly beyond said edge, said distal edge of said bar being spaced slightly from said rod in said locking position.
 5. The structure of claim 4 wherein the upper corner of said extension bar adjacent said distal edge is curved to facilitate rotation of said clamping bracket to said release position.
 6. The structure of claim 4 wherein the height of said clamping bracket is substantially the same as the height of said bar and wherein the pivot position of said clamping bracket is above the vertical midpoint of said bar, whereby downward force is exerted on said stirrup assembly in a clamping position will enhance clamping action of said rod.
 7. The structure of claim 1 wherein said bar is provided with a bore extending transverse of the axis of said support rod, said structuRe further comprising a dowel pin fitted in said bore and having an exposed lateral area extending beyond the distal end of said bar and adapted to engage said rod and clamp the same in said locking position. 